1. Field of the Disclosure
The disclosure relates to a vacuum pump, in particular a turbomolecular pump.
2. Discussion of the Background Art
Vacuum pumps have a rotor shaft that typically is connected with a plurality of rotor elements. With a turbomolecular pimp, for example, the rotor elements are a plurality of rotor discs extending substantially radially with respect to the rotor shaft. Stator discs usually connected with a housing or arranged in the housing are provided between the rotor discs, so that the stator discs are a plurality of individual stator means. The individual stator discs are thus arranged between adjacent rotor discs. Similarly, a rotor element may be, for example, formed by rotating elements of a Holweck stage, a Siegbahn stage or a Gaede stage, as well as a rotor of a side-channel compressor. Due to compression, high temperatures occur in particular in such types of pumps. The rotor shaft of the vacuum pump is further connected with a drive means, such as a, electric motor. Such components also often generate high temperatures. It is thus required to cool such components that generate large amounts of heat.
The rotor shaft is supported by bearings. Rolling bearings in particular are temperature-sensitive, however. At high operating temperatures the service life of the rolling bearings is shortened. Often, the bearings, in particular the bearing on the pressure side, are arranged in a confined installation space and thus close to the electric drive unit, as well as to the region where a high compression of gas occurs and thus a large quantity of dissipated heat is generated. As a consequence, the bearings are operated at a high operating temperature.
It is an object of the disclosure to reduce the operating temperature of bearings, in particular rolling bearings, in vacuum pumps using constructionally simple means.